<p>This study presents a theoretical investigation of two immiscible non-Newtonian fluids such as Jeffrey and Casson types flowing in a vertical microchannel under the combined effects of electroosmosis, magnetic field, Hall current, buoyancy-driven convection, thermal radiation, and internal heat generation. Distinct governing equations are formulated for each fluid based on their rheological properties and solved analytically with appropriate interfacial and boundary conditions. The model introduces key non-dimensional parameters to capture the influence of electrokinetic and magnetohydrodynamic forces on fluid motion and heat transfer. The novelty of this work lies in its integration of multiple physical effects into an exact analytical framework for immiscible non-Newtonian fluid dynamics in microchannels. The results reveal that electroosmosis enhances flow velocity. Internal heat generation and radiation elevate the temperature profile, whereas higher Prandtl numbers suppress it. These findings offer valuable insights for optimizing complex fluid systems in confined geometries. Applications of this study also include the design of microfluidic devices, thermal management systems, and biomedical transport technologies.</p>